And while we're at the Technical Brain, their TBC-Zero stereo control amplifier is something I'll explore more intimately in not too distant future. TBC-Zero is fully balanced preamplifier with no negative feedback and uses unique circuit technology that guarantees stable operation without any emitter resistors...

Here are the highlights

Eradication of sound deterioration factors
No emitter resistors
Revolutionary circuit technology that guarantees stable operation without any emitter resistors* 
Specially developed duplex temperature compensation
Meticulously tested and matched transistors
Newly developed differential DC servo circuit
The circuit with a flat response from DC to high frequencies assures a stable operation of the non-
feedback amplifier. This results in no group delay from DC to 500kHz and high coherency. Large-capacity power circuit
Specially developed hand-wound flat-coil transformers with EI core that have very low magnetic flux
Ideal chassis design and component composition
Painstaking arrangement of components and wiring for the elimination of noise and vibration


Maximum output power: 10Vrms
Frequency response: DC to 500kHz (-3dB)
Circuitry: Fully balanced DC with no feedback
Amplifier: FET and bipolar transistors
Input terminal: Cannon 3P connector (balanced) x4; RCA (unbalanced) x4 Input impedance: 10 - 20k  (balanced); 5 - 15k  (unbalanced)
Output impedance: 94  (balanced); 47  (unbalanced) Gain: 12dB approx.
Distortion: 0.02% max./ 20Hz - 20kHz at 5V rms output Additional feature: Circuit breaker for power switch

General Information

Colour: Silver or Japanese lacquered black (special order)
Body: Aluminum
Power requirement: AC100/117V 50/60Hz, 45W
Size: 346 x 200 x 425mm (13.62 x 7.87 x 16.73inches)
Weight: 20kg approx. (44.1lbs approx.)
Handcrafted in Japan only with specially selected Japan-made parts